A 55-year-old on-duty sentry posted at the Air Force unit in Kalina opened fire at his colleagues who were asleep in their barracks at the gate early Tuesday morning, killing two of them and injuring two others.

The injured are being treated at the Navy hospital in Colaba, INHS Asvini, where their condition is said to be stable, Air Force sources said.

Around three hours after the incident that took place at 1.15 am, the suspect was caught by the police nine kilometres away from the scene of crime as he tried to flee in an autorickshaw.

The suspect, identified as Lance Naik R S Yadav, a native of Rajasthan, has reportedly confessed to the police that he planned the attack as a revenge for the “constant ragging and harassment” they subjected him to. The deceased have been identified as Somdatta and H K Singh.

All five are ex-servicemen and part of Defence Security Corps employed as guards at the Air Force station’s entrance gates. Yadav had been in the job for the past 10 years.

According to Namdeo Chavan, deputy commissioner of police (zone 8), Vijendra, an eyewitness and colleague of the suspect, has told the police that Yadav seemed in a frenzy and had fired five rounds.

Vijendra told the police he was woken up by the sound of bullets and that he even managed to briefly grab Yadav and push his rifle away from the direction of the colleagues who were sleeping.

Chavan said Yadav managed to free himself of Vijendra’s hold and ran outside, leaving his slippers behind. “He was last seen running towards the highway, away from the service road and heading northwards,” the DCP added.

Soon after the incident, Vijendra called the police after which the four men were rushed to V N Desai hospital, where Somdatta and H K Singh were declared brought dead. The other two injured were shifted to the Navy hospital in Colaba.

“Vijendra told us Yadav was barefoot and wearing uniform of the Defense Security Corps (DSC). We relayed the information on the wireless. Within half-an-hour, a constable at the Vanrai police chowkie, who was on night patrolling, saw a man in uniform travelling in an autorickshaw. He nabbed Yadav and informed us,” said Chavan.

“Yadav claims the seven men who worked with him ragged him. He says they always ganged up against him and ensured he was given night shift while they managed day duty for themselves. He says he wanted to kill all of them and would have continued firing at them had he not been stopped,” said Chavan.

The police, however, also suspect that Yadav was debt to repay. “His colleagues say they used to borrow money from each other frequently. We are investigating this angle too,” said the officer.